The present invention relates generally to tools for removing threaded fasteners.
It can be difficult to remove a nut, stud, sleeve or similar fastener after it has become frozen in place over time because of heat, strain and/or corrosion. The difficulty in removal is compounded when the fastener has a threaded cylindrical outer surface, making the vital step of obtaining a satisfactory grip on the object substantially more arduous. Even more difficult is the removal of a threaded collar or fastener which is screwed onto a threaded stud which must not be damaged in the removal of the fastener, e.g., in removing a bud nut on a truck or other vehicle.
The conventional method of removing such a fastener involved the application of heat with e.g., an acetylene torch in combination with the application of whatever brute mechanical force can be applied. If this fails, the threaded collar may be burned off using an acetylene cutting torch. Alternatively, where the threaded collar is a bud nut on a stud on the hub of a track, it can be removed by removing the hub assembly from the axle of the truck and unbolting the stud from the brake drum.
A frequent requirement for removing a frozen or damaged fastener is on the wheels of large trucks which have threaded studs bolted onto wheel hubs. Bud nuts are used in part to prevent damage to these threaded studs. A bud nut is essentially a hollow cylinder threaded on the inside (to screw onto a stud) and threaded on the outside (allowing the wheel of the truck to be placed over the bud nut, with a lug nut being screwed onto its threaded exterior to secure the wheel on the hub). Each but nut has a radially outwardly extending shoulder on its bottom end. The shoulder fits into a beveled aperture in the truck wheel rim.
But nuts are frequently damaged when the inner rim is removed (e.g., to repair or replace a tire). The bud nuts must then be removed and replaced. A square gripping surface at the top of the bud nut is provided to facilitate installation and removal of the bud nut. The square gripping surface is smaller than the diameter of the outer threaded surface of the bud nut to allow a lug nut to be installed onto the bud nut. Unfortunately, due to the high forces involved, the square gripping surface often breaks off of the bud nut, leaving only a short cylinder or segment portion of the bud nut (threaded on the inside and outside) screwed onto the stud. It is then exceptionally difficult to remove this remaining segment of the bud nut without damaging the stud.
As a further complication, the studs on the wheel hubs on the left (or drivers) side of a truck have left hand threads whereas the studs on the wheel hubs on the right (or passenger) side of a truck have right hand threads. Therefore bud nuts may have either left hand thread or right hand thread, depending on which side of the truck they are used on. Consequently, removal capability in both directions is necessary.
It is therefore an object of the invention to provide a tool for removing threaded fasteners.
It is another object of the invention to provide a tool which will easily remove even a bud nut which is broken off near the radially outwardly extending shoulder at the bottom thereof.
It is a further object of the invention to provide a tool capable of gripping a minimal remaining portion of a bud nut without damaging the threads on the threaded stud on which the bud nut is mounted.
It is yet another object of the present invention to provide such a tool which has a minimal number of parts, is sturdy in construction and highly durable, while remaining relatively simple and economical to manufacture and use.